A downlight wall wash is a type of recessed light fixture, which is mounted in a ceiling. The wall wash is used to distribute light onto a wall that is adjacent to the light fixture. Lighting designers use various criteria to evaluate the quality of such a light fixture, such as how well the fixture can distribute light on the adjacent wall. Ideally, lighting designers would like to have the light distributed evenly on the wall with the light directed very close to the ceiling and a smooth transition down the wall toward the floor. Multiple wall washers, which are arranged next to each other, can be used to eliminate arch type of distribution (called scallops) and create a wall pattern that is very uniform horizontally across the wall and vertically, with no variation in foot candles.
Light-emitting diodes (LEDs) have become a viable light source for downlights. However, manufacturers continue to design wall wash reflectors using the same type of configurations and shapes that are used with a traditional light source that generates light in all directions. There are two commonly used approaches to perform wall-wash. For example, the first approach is to use a wall wash lighting assembly that consists of a parabolic trim with a window cut out and replaced with a redirecting partial parabolic kicker. The first approach has the benefits of a suitably high-ceiling illumination but suffers from uniformity distribution on the adjacent wall. For example, as shown in FIG. 6, the light distributed on an adjacent wall has a large gradient of light to dark resulting in poor uniformity. The second approach is to use a wall wash lighting assembly that consists of an angle-cut trim and a linear spread lens. The angle cut trim is used to aim light toward the adjacent wall, and the linear spread lens is used to distribute light evenly on the wall. The second approach is, however, unable to provide for a high-ceiling illumination, as shown in FIG. 7.